+ CREATE DEF_USE (DU) and / or USE_DEF (UD) CHAINS
+
+ Link either the defs to the uses and / or the uses to the defs.
+
+ These problems are set up like the other dataflow problems so that
+ they nicely fit into the framework. They are much simpler and only
+ involve a single traversal of instructions and an examination of
+ the reaching defs information (the dependent problem).
+----------------------------------------------------------------------------*/
+
+#define df_chain_problem_p(FLAG) (((enum df_chain_flags)df_chain->local_flags)&(FLAG))
+
+/* Create a du or ud chain from SRC to DST and link it into SRC. */
+
+struct df_link *
+df_chain_create (df_ref src, df_ref dst)
+{
+ struct df_link *head = DF_REF_CHAIN (src);
+ struct df_link *link = (struct df_link *) pool_alloc (df_chain->block_pool);
+
+ DF_REF_CHAIN (src) = link;
+ link->next = head;
+ link->ref = dst;
+ return link;
+}
+
+
+/* Delete any du or ud chains that start at REF and point to
+ TARGET. */
+static void
+df_chain_unlink_1 (df_ref ref, df_ref target)
+{
+ struct df_link *chain = DF_REF_CHAIN (ref);
+ struct df_link *prev = NULL;
+
+ while (chain)
+ {
+ if (chain->ref == target)
+ {
+ if (prev)
+ prev->next = chain->next;
+ else
+ DF_REF_CHAIN (ref) = chain->next;
+ pool_free (df_chain->block_pool, chain);
+ return;
+ }
+ prev = chain;
+ chain = chain->next;
+ }
+}
+
+
+/* Delete a du or ud chain that leave or point to REF. */
+
+void
+df_chain_unlink (df_ref ref)
+{
+ struct df_link *chain = DF_REF_CHAIN (ref);
+ while (chain)
+ {
+ struct df_link *next = chain->next;
+ /* Delete the other side if it exists. */
+ df_chain_unlink_1 (chain->ref, ref);
+ pool_free (df_chain->block_pool, chain);
+ chain = next;
+ }
+ DF_REF_CHAIN (ref) = NULL;
+}
+
+
+/* Copy the du or ud chain starting at FROM_REF and attach it to
+ TO_REF. */
+
+void
+df_chain_copy (df_ref to_ref,
+ struct df_link *from_ref)
+{
+ while (from_ref)
+ {
+ df_chain_create (to_ref, from_ref->ref);
+ from_ref = from_ref->next;
+ }
+}
+
+
+/* Remove this problem from the stack of dataflow problems. */
+
+static void
+df_chain_remove_problem (void)
+{
+ bitmap_iterator bi;
+ unsigned int bb_index;
+
+ /* Wholesale destruction of the old chains. */
+ if (df_chain->block_pool)
+ free_alloc_pool (df_chain->block_pool);
+
+ EXECUTE_IF_SET_IN_BITMAP (df_chain->out_of_date_transfer_functions, 0, bb_index, bi)
+ {
+ rtx insn;
+ df_ref *def_rec;
+ df_ref *use_rec;
+ basic_block bb = BASIC_BLOCK (bb_index);
+
+ if (df_chain_problem_p (DF_DU_CHAIN))
+ for (def_rec = df_get_artificial_defs (bb->index); *def_rec; def_rec++)
+ DF_REF_CHAIN (*def_rec) = NULL;
+ if (df_chain_problem_p (DF_UD_CHAIN))
+ for (use_rec = df_get_artificial_uses (bb->index); *use_rec; use_rec++)
+ DF_REF_CHAIN (*use_rec) = NULL;
+
+ FOR_BB_INSNS (bb, insn)
+ {
+ unsigned int uid = INSN_UID (insn);
+
+ if (INSN_P (insn))
+ {
+ if (df_chain_problem_p (DF_DU_CHAIN))
+ for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
+ DF_REF_CHAIN (*def_rec) = NULL;
+ if (df_chain_problem_p (DF_UD_CHAIN))
+ {
+ for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
+ DF_REF_CHAIN (*use_rec) = NULL;
+ for (use_rec = DF_INSN_UID_EQ_USES (uid); *use_rec; use_rec++)
+ DF_REF_CHAIN (*use_rec) = NULL;
+ }
+ }
+ }
+ }
+
+ bitmap_clear (df_chain->out_of_date_transfer_functions);
+ df_chain->block_pool = NULL;
+}
+
+
+/* Remove the chain problem completely. */
+
+static void
+df_chain_fully_remove_problem (void)
+{
+ df_chain_remove_problem ();
+ BITMAP_FREE (df_chain->out_of_date_transfer_functions);
+ free (df_chain);
+}
+
+
+/* Create def-use or use-def chains. */
+
+static void
+df_chain_alloc (bitmap all_blocks ATTRIBUTE_UNUSED)
+{
+ df_chain_remove_problem ();
+ df_chain->block_pool = create_alloc_pool ("df_chain_block pool",
+ sizeof (struct df_link), 50);
+ df_chain->optional_p = true;
+}
+
+
+/* Reset all of the chains when the set of basic blocks changes. */
+
+static void
+df_chain_reset (bitmap blocks_to_clear ATTRIBUTE_UNUSED)
+{
+ df_chain_remove_problem ();
+}
+
+
+/* Create the chains for a list of USEs. */
+
+static void
+df_chain_create_bb_process_use (bitmap local_rd,
+ df_ref *use_rec,
+ int top_flag)
+{
+ bitmap_iterator bi;
+ unsigned int def_index;
+
+ while (*use_rec)
+ {
+ df_ref use = *use_rec;
+ unsigned int uregno = DF_REF_REGNO (use);
+ if ((!(df->changeable_flags & DF_NO_HARD_REGS))
+ || (uregno >= FIRST_PSEUDO_REGISTER))
+ {
+ /* Do not want to go through this for an uninitialized var. */
+ int count = DF_DEFS_COUNT (uregno);
+ if (count)
+ {
+ if (top_flag == (DF_REF_FLAGS (use) & DF_REF_AT_TOP))
+ {
+ unsigned int first_index = DF_DEFS_BEGIN (uregno);
+ unsigned int last_index = first_index + count - 1;
+
+ EXECUTE_IF_SET_IN_BITMAP (local_rd, first_index, def_index, bi)
+ {
+ df_ref def;
+ if (def_index > last_index)
+ break;
+
+ def = DF_DEFS_GET (def_index);
+ if (df_chain_problem_p (DF_DU_CHAIN))
+ df_chain_create (def, use);
+ if (df_chain_problem_p (DF_UD_CHAIN))
+ df_chain_create (use, def);
+ }
+ }
+ }
+ }
+
+ use_rec++;
+ }
+}
+
+
+/* Create chains from reaching defs bitmaps for basic block BB. */
+
+static void
+df_chain_create_bb (unsigned int bb_index)
+{
+ basic_block bb = BASIC_BLOCK (bb_index);
+ struct df_rd_bb_info *bb_info = df_rd_get_bb_info (bb_index);
+ rtx insn;
+ bitmap cpy = BITMAP_ALLOC (NULL);
+
+ bitmap_copy (cpy, bb_info->in);
+ bitmap_set_bit (df_chain->out_of_date_transfer_functions, bb_index);
+
+ /* Since we are going forwards, process the artificial uses first
+ then the artificial defs second. */
+
+#ifdef EH_USES
+ /* Create the chains for the artificial uses from the EH_USES at the
+ beginning of the block. */
+
+ /* Artificials are only hard regs. */
+ if (!(df->changeable_flags & DF_NO_HARD_REGS))
+ df_chain_create_bb_process_use (cpy,
+ df_get_artificial_uses (bb->index),
+ DF_REF_AT_TOP);
+#endif
+
+ df_rd_simulate_artificial_defs_at_top (bb, cpy);
+
+ /* Process the regular instructions next. */
+ FOR_BB_INSNS (bb, insn)
+ if (INSN_P (insn))
+ {
+ unsigned int uid = INSN_UID (insn);
+
+ /* First scan the uses and link them up with the defs that remain
+ in the cpy vector. */
+ df_chain_create_bb_process_use (cpy, DF_INSN_UID_USES (uid), 0);
+ if (df->changeable_flags & DF_EQ_NOTES)
+ df_chain_create_bb_process_use (cpy, DF_INSN_UID_EQ_USES (uid), 0);
+
+ /* Since we are going forwards, process the defs second. */
+ df_rd_simulate_one_insn (bb, insn, cpy);
+ }
+
+ /* Create the chains for the artificial uses of the hard registers
+ at the end of the block. */
+ if (!(df->changeable_flags & DF_NO_HARD_REGS))
+ df_chain_create_bb_process_use (cpy,
+ df_get_artificial_uses (bb->index),
+ 0);
+
+ BITMAP_FREE (cpy);
+}
+
+/* Create def-use chains from reaching use bitmaps for basic blocks
+ in BLOCKS. */
+
+static void
+df_chain_finalize (bitmap all_blocks)
+{
+ unsigned int bb_index;
+ bitmap_iterator bi;
+
+ EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
+ {
+ df_chain_create_bb (bb_index);
+ }
+}
+
+
+/* Free all storage associated with the problem. */
+
+static void
+df_chain_free (void)
+{
+ free_alloc_pool (df_chain->block_pool);
+ BITMAP_FREE (df_chain->out_of_date_transfer_functions);
+ free (df_chain);
+}
+
+
+/* Debugging info. */
+
+static void
+df_chain_top_dump (basic_block bb, FILE *file)
+{
+ if (df_chain_problem_p (DF_DU_CHAIN))
+ {
+ rtx insn;
+ df_ref *def_rec = df_get_artificial_defs (bb->index);
+ if (*def_rec)
+ {
+
+ fprintf (file, ";; DU chains for artificial defs\n");
+ while (*def_rec)
+ {
+ df_ref def = *def_rec;
+ fprintf (file, ";; reg %d ", DF_REF_REGNO (def));
+ df_chain_dump (DF_REF_CHAIN (def), file);
+ fprintf (file, "\n");
+ def_rec++;
+ }
+ }
+
+ FOR_BB_INSNS (bb, insn)
+ {
+ if (INSN_P (insn))
+ {
+ struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
+ def_rec = DF_INSN_INFO_DEFS (insn_info);
+ if (*def_rec)
+ {
+ fprintf (file, ";; DU chains for insn luid %d uid %d\n",
+ DF_INSN_INFO_LUID (insn_info), INSN_UID (insn));
+
+ while (*def_rec)
+ {
+ df_ref def = *def_rec;
+ fprintf (file, ";; reg %d ", DF_REF_REGNO (def));
+ if (DF_REF_FLAGS (def) & DF_REF_READ_WRITE)
+ fprintf (file, "read/write ");
+ df_chain_dump (DF_REF_CHAIN (def), file);
+ fprintf (file, "\n");
+ def_rec++;
+ }
+ }
+ }
+ }
+ }
+}
+
+
+static void
+df_chain_bottom_dump (basic_block bb, FILE *file)
+{
+ if (df_chain_problem_p (DF_UD_CHAIN))
+ {
+ rtx insn;
+ df_ref *use_rec = df_get_artificial_uses (bb->index);
+
+ if (*use_rec)
+ {
+ fprintf (file, ";; UD chains for artificial uses\n");
+ while (*use_rec)
+ {
+ df_ref use = *use_rec;
+ fprintf (file, ";; reg %d ", DF_REF_REGNO (use));
+ df_chain_dump (DF_REF_CHAIN (use), file);
+ fprintf (file, "\n");
+ use_rec++;
+ }
+ }
+
+ FOR_BB_INSNS (bb, insn)
+ {
+ if (INSN_P (insn))
+ {
+ struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
+ df_ref *eq_use_rec = DF_INSN_INFO_EQ_USES (insn_info);
+ use_rec = DF_INSN_INFO_USES (insn_info);
+ if (*use_rec || *eq_use_rec)
+ {
+ fprintf (file, ";; UD chains for insn luid %d uid %d\n",
+ DF_INSN_INFO_LUID (insn_info), INSN_UID (insn));
+
+ while (*use_rec)
+ {
+ df_ref use = *use_rec;
+ fprintf (file, ";; reg %d ", DF_REF_REGNO (use));
+ if (DF_REF_FLAGS (use) & DF_REF_READ_WRITE)
+ fprintf (file, "read/write ");
+ df_chain_dump (DF_REF_CHAIN (use), file);
+ fprintf (file, "\n");
+ use_rec++;
+ }
+ while (*eq_use_rec)
+ {
+ df_ref use = *eq_use_rec;
+ fprintf (file, ";; eq_note reg %d ", DF_REF_REGNO (use));
+ df_chain_dump (DF_REF_CHAIN (use), file);
+ fprintf (file, "\n");
+ eq_use_rec++;
+ }
+ }
+ }
+ }
+ }
+}
+
+
+static struct df_problem problem_CHAIN =
+{
+ DF_CHAIN, /* Problem id. */
+ DF_NONE, /* Direction. */
+ df_chain_alloc, /* Allocate the problem specific data. */
+ df_chain_reset, /* Reset global information. */
+ NULL, /* Free basic block info. */
+ NULL, /* Local compute function. */
+ NULL, /* Init the solution specific data. */
+ NULL, /* Iterative solver. */
+ NULL, /* Confluence operator 0. */
+ NULL, /* Confluence operator n. */
+ NULL, /* Transfer function. */
+ df_chain_finalize, /* Finalize function. */
+ df_chain_free, /* Free all of the problem information. */
+ df_chain_fully_remove_problem,/* Remove this problem from the stack of dataflow problems. */
+ NULL, /* Debugging. */
+ df_chain_top_dump, /* Debugging start block. */
+ df_chain_bottom_dump, /* Debugging end block. */
+ NULL, /* Incremental solution verify start. */
+ NULL, /* Incremental solution verify end. */
+ &problem_RD, /* Dependent problem. */
+ TV_DF_CHAIN, /* Timing variable. */
+ false /* Reset blocks on dropping out of blocks_to_analyze. */
+};
+
+
+/* Create a new DATAFLOW instance and add it to an existing instance
+ of DF. The returned structure is what is used to get at the
+ solution. */
+
+void
+df_chain_add_problem (unsigned int chain_flags)
+{
+ df_add_problem (&problem_CHAIN);
+ df_chain->local_flags = chain_flags;
+ df_chain->out_of_date_transfer_functions = BITMAP_ALLOC (NULL);
+}
+
+#undef df_chain_problem_p
+
+\f
+/*----------------------------------------------------------------------------
+ BYTE LEVEL LIVE REGISTERS
+
+ Find the locations in the function where any use of a pseudo can
+ reach in the backwards direction. In and out bitvectors are built
+ for each basic block. There are two mapping functions,
+ df_byte_lr_get_regno_start and df_byte_lr_get_regno_len that are
+ used to map regnos into bit vector positions.
+
+ This problem differs from the regular df_lr function in the way
+ that subregs, *_extracts and strict_low_parts are handled. In lr
+ these are consider partial kills, here, the exact set of bytes is
+ modeled. Note that any reg that has none of these operations is
+ only modeled with a single bit since all operations access the
+ entire register.
+
+ This problem is more brittle that the regular lr. It currently can
+ be used in dce incrementally, but cannot be used in an environment
+ where insns are created or modified. The problem is that the
+ mapping of regnos to bitmap positions is relatively compact, in
+ that if a pseudo does not do any of the byte wise operations, only
+ one slot is allocated, rather than a slot for each byte. If insn
+ are created, where a subreg is used for a reg that had no subregs,
+ the mapping would be wrong. Likewise, there are no checks to see
+ that new pseudos have been added. These issues could be addressed
+ by adding a problem specific flag to not use the compact mapping,
+ if there was a need to do so.
+
+ ----------------------------------------------------------------------------*/
+
+/* Private data used to verify the solution for this problem. */
+struct df_byte_lr_problem_data
+{
+ /* Expanded versions of bitvectors used in lr. */
+ bitmap invalidated_by_call;
+ bitmap hardware_regs_used;
+
+ /* Indexed by regno, this is true if there are subregs, extracts or
+ strict_low_parts for this regno. */
+ bitmap needs_expansion;
+
+ /* The start position and len for each regno in the various bit
+ vectors. */
+ unsigned int* regno_start;
+ unsigned int* regno_len;
+ /* An obstack for the bitmaps we need for this problem. */
+ bitmap_obstack byte_lr_bitmaps;
+};
+
+
+/* Get the starting location for REGNO in the df_byte_lr bitmaps. */
+
+int
+df_byte_lr_get_regno_start (unsigned int regno)
+{
+ struct df_byte_lr_problem_data *problem_data
+ = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;;
+ return problem_data->regno_start[regno];
+}
+
+
+/* Get the len for REGNO in the df_byte_lr bitmaps. */
+
+int
+df_byte_lr_get_regno_len (unsigned int regno)
+{
+ struct df_byte_lr_problem_data *problem_data
+ = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;;
+ return problem_data->regno_len[regno];
+}
+
+
+/* Set basic block info. */
+
+static void
+df_byte_lr_set_bb_info (unsigned int index,
+ struct df_byte_lr_bb_info *bb_info)
+{
+ gcc_assert (df_byte_lr);
+ gcc_assert (index < df_byte_lr->block_info_size);
+ df_byte_lr->block_info[index] = bb_info;
+}
+
+
+/* Free basic block info. */
+
+static void
+df_byte_lr_free_bb_info (basic_block bb ATTRIBUTE_UNUSED,
+ void *vbb_info)
+{
+ struct df_byte_lr_bb_info *bb_info = (struct df_byte_lr_bb_info *) vbb_info;
+ if (bb_info)
+ {
+ BITMAP_FREE (bb_info->use);
+ BITMAP_FREE (bb_info->def);
+ BITMAP_FREE (bb_info->in);
+ BITMAP_FREE (bb_info->out);
+ pool_free (df_byte_lr->block_pool, bb_info);
+ }
+}
+
+
+/* Check all of the refs in REF_REC to see if any of them are
+ extracts, subregs or strict_low_parts. */
+
+static void
+df_byte_lr_check_regs (df_ref *ref_rec)
+{
+ struct df_byte_lr_problem_data *problem_data
+ = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
+
+ for (; *ref_rec; ref_rec++)
+ {
+ df_ref ref = *ref_rec;
+ if (DF_REF_FLAGS_IS_SET (ref, DF_REF_SIGN_EXTRACT
+ | DF_REF_ZERO_EXTRACT
+ | DF_REF_STRICT_LOW_PART)
+ || GET_CODE (DF_REF_REG (ref)) == SUBREG)
+ bitmap_set_bit (problem_data->needs_expansion, DF_REF_REGNO (ref));
+ }
+}
+
+
+/* Expand bitmap SRC which is indexed by regno to DEST which is indexed by
+ regno_start and regno_len. */
+
+static void
+df_byte_lr_expand_bitmap (bitmap dest, bitmap src)
+{
+ struct df_byte_lr_problem_data *problem_data
+ = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
+ bitmap_iterator bi;
+ unsigned int i;
+
+ bitmap_clear (dest);
+ EXECUTE_IF_SET_IN_BITMAP (src, 0, i, bi)
+ {
+ bitmap_set_range (dest, problem_data->regno_start[i],
+ problem_data->regno_len[i]);
+ }
+}
+
+
+/* Allocate or reset bitmaps for DF_BYTE_LR blocks. The solution bits are
+ not touched unless the block is new. */
+
+static void
+df_byte_lr_alloc (bitmap all_blocks ATTRIBUTE_UNUSED)
+{
+ unsigned int bb_index;
+ bitmap_iterator bi;
+ basic_block bb;
+ unsigned int regno;
+ unsigned int index = 0;
+ unsigned int max_reg = max_reg_num();
+ struct df_byte_lr_problem_data *problem_data
+ = XNEW (struct df_byte_lr_problem_data);
+
+ df_byte_lr->problem_data = problem_data;
+
+ if (!df_byte_lr->block_pool)
+ df_byte_lr->block_pool = create_alloc_pool ("df_byte_lr_block pool",
+ sizeof (struct df_byte_lr_bb_info), 50);
+
+ df_grow_bb_info (df_byte_lr);
+
+ /* Create the mapping from regnos to slots. This does not change
+ unless the problem is destroyed and recreated. In particular, if
+ we end up deleting the only insn that used a subreg, we do not
+ want to redo the mapping because this would invalidate everything
+ else. */
+
+ bitmap_obstack_initialize (&problem_data->byte_lr_bitmaps);
+ problem_data->regno_start = XNEWVEC (unsigned int, max_reg);
+ problem_data->regno_len = XNEWVEC (unsigned int, max_reg);
+ problem_data->hardware_regs_used = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
+ problem_data->invalidated_by_call = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
+ problem_data->needs_expansion = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
+
+ /* Discover which regno's use subregs, extracts or
+ strict_low_parts. */
+ FOR_EACH_BB (bb)
+ {
+ rtx insn;
+ FOR_BB_INSNS (bb, insn)
+ {
+ if (INSN_P (insn))
+ {
+ struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
+ df_byte_lr_check_regs (DF_INSN_INFO_DEFS (insn_info));
+ df_byte_lr_check_regs (DF_INSN_INFO_USES (insn_info));
+ }
+ }
+ bitmap_set_bit (df_byte_lr->out_of_date_transfer_functions, bb->index);
+ }
+
+ bitmap_set_bit (df_byte_lr->out_of_date_transfer_functions, ENTRY_BLOCK);
+ bitmap_set_bit (df_byte_lr->out_of_date_transfer_functions, EXIT_BLOCK);
+
+ /* Allocate the slots for each regno. */
+ for (regno = 0; regno < max_reg; regno++)
+ {
+ int len;
+ problem_data->regno_start[regno] = index;
+ if (bitmap_bit_p (problem_data->needs_expansion, regno))
+ len = GET_MODE_SIZE (GET_MODE (regno_reg_rtx[regno]));
+ else
+ len = 1;
+
+ problem_data->regno_len[regno] = len;
+ index += len;
+ }
+
+ df_byte_lr_expand_bitmap (problem_data->hardware_regs_used,
+ df->hardware_regs_used);
+ df_byte_lr_expand_bitmap (problem_data->invalidated_by_call,
+ regs_invalidated_by_call_regset);
+
+ EXECUTE_IF_SET_IN_BITMAP (df_byte_lr->out_of_date_transfer_functions, 0, bb_index, bi)
+ {
+ struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb_index);
+ if (bb_info)
+ {
+ bitmap_clear (bb_info->def);
+ bitmap_clear (bb_info->use);
+ }
+ else
+ {
+ bb_info = (struct df_byte_lr_bb_info *) pool_alloc (df_byte_lr->block_pool);
+ df_byte_lr_set_bb_info (bb_index, bb_info);
+ bb_info->use = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
+ bb_info->def = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
+ bb_info->in = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
+ bb_info->out = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
+ }
+ }
+
+ df_byte_lr->optional_p = true;
+}
+
+
+/* Reset the global solution for recalculation. */
+
+static void
+df_byte_lr_reset (bitmap all_blocks)
+{
+ unsigned int bb_index;
+ bitmap_iterator bi;
+
+ EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
+ {
+ struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb_index);
+ gcc_assert (bb_info);
+ bitmap_clear (bb_info->in);
+ bitmap_clear (bb_info->out);
+ }
+}
+
+
+/* Compute local live register info for basic block BB. */
+
+static void
+df_byte_lr_bb_local_compute (unsigned int bb_index)
+{
+ struct df_byte_lr_problem_data *problem_data
+ = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
+ basic_block bb = BASIC_BLOCK (bb_index);
+ struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb_index);
+ rtx insn;
+ df_ref *def_rec;
+ df_ref *use_rec;
+
+ /* Process the registers set in an exception handler. */
+ for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
+ {
+ df_ref def = *def_rec;
+ if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0)
+ {
+ unsigned int dregno = DF_REF_REGNO (def);
+ unsigned int start = problem_data->regno_start[dregno];
+ unsigned int len = problem_data->regno_len[dregno];
+ bitmap_set_range (bb_info->def, start, len);
+ bitmap_clear_range (bb_info->use, start, len);
+ }
+ }
+
+ /* Process the hardware registers that are always live. */
+ for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
+ {
+ df_ref use = *use_rec;
+ /* Add use to set of uses in this BB. */
+ if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0)
+ {
+ unsigned int uregno = DF_REF_REGNO (use);
+ unsigned int start = problem_data->regno_start[uregno];
+ unsigned int len = problem_data->regno_len[uregno];
+ bitmap_set_range (bb_info->use, start, len);
+ }
+ }
+
+ FOR_BB_INSNS_REVERSE (bb, insn)
+ {
+ unsigned int uid = INSN_UID (insn);
+
+ if (!INSN_P (insn))
+ continue;
+
+ for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
+ {
+ df_ref def = *def_rec;
+ /* If the def is to only part of the reg, it does
+ not kill the other defs that reach here. */
+ if (!(DF_REF_FLAGS (def) & (DF_REF_CONDITIONAL)))
+ {
+ unsigned int dregno = DF_REF_REGNO (def);
+ unsigned int start = problem_data->regno_start[dregno];
+ unsigned int len = problem_data->regno_len[dregno];
+ unsigned int sb;
+ unsigned int lb;
+ if (!df_compute_accessed_bytes (def, DF_MM_MUST, &sb, &lb))
+ {
+ start += sb;
+ len = lb - sb;
+ }
+ if (len)
+ {
+ bitmap_set_range (bb_info->def, start, len);
+ bitmap_clear_range (bb_info->use, start, len);
+ }
+ }
+ }
+
+ for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
+ {
+ df_ref use = *use_rec;
+ unsigned int uregno = DF_REF_REGNO (use);
+ unsigned int start = problem_data->regno_start[uregno];
+ unsigned int len = problem_data->regno_len[uregno];
+ unsigned int sb;
+ unsigned int lb;
+ if (!df_compute_accessed_bytes (use, DF_MM_MAY, &sb, &lb))
+ {
+ start += sb;
+ len = lb - sb;
+ }
+ /* Add use to set of uses in this BB. */
+ if (len)
+ bitmap_set_range (bb_info->use, start, len);
+ }
+ }
+
+ /* Process the registers set in an exception handler or the hard
+ frame pointer if this block is the target of a non local
+ goto. */
+ for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
+ {
+ df_ref def = *def_rec;
+ if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
+ {
+ unsigned int dregno = DF_REF_REGNO (def);
+ unsigned int start = problem_data->regno_start[dregno];
+ unsigned int len = problem_data->regno_len[dregno];
+ bitmap_set_range (bb_info->def, start, len);
+ bitmap_clear_range (bb_info->use, start, len);
+ }
+ }
+
+#ifdef EH_USES
+ /* Process the uses that are live into an exception handler. */
+ for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
+ {
+ df_ref use = *use_rec;
+ /* Add use to set of uses in this BB. */
+ if (DF_REF_FLAGS (use) & DF_REF_AT_TOP)
+ {
+ unsigned int uregno = DF_REF_REGNO (use);
+ unsigned int start = problem_data->regno_start[uregno];
+ unsigned int len = problem_data->regno_len[uregno];
+ bitmap_set_range (bb_info->use, start, len);
+ }
+ }
+#endif
+}
+
+
+/* Compute local live register info for each basic block within BLOCKS. */
+
+static void
+df_byte_lr_local_compute (bitmap all_blocks ATTRIBUTE_UNUSED)
+{
+ unsigned int bb_index;
+ bitmap_iterator bi;
+
+ EXECUTE_IF_SET_IN_BITMAP (df_byte_lr->out_of_date_transfer_functions, 0, bb_index, bi)
+ {
+ if (bb_index == EXIT_BLOCK)
+ {
+ /* The exit block is special for this problem and its bits are
+ computed from thin air. */
+ struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (EXIT_BLOCK);
+ df_byte_lr_expand_bitmap (bb_info->use, df->exit_block_uses);
+ }
+ else
+ df_byte_lr_bb_local_compute (bb_index);
+ }
+
+ bitmap_clear (df_byte_lr->out_of_date_transfer_functions);
+}
+
+
+/* Initialize the solution vectors. */
+
+static void
+df_byte_lr_init (bitmap all_blocks)
+{
+ unsigned int bb_index;
+ bitmap_iterator bi;
+
+ EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
+ {
+ struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb_index);
+ bitmap_copy (bb_info->in, bb_info->use);
+ bitmap_clear (bb_info->out);
+ }
+}
+
+
+/* Confluence function that processes infinite loops. This might be a
+ noreturn function that throws. And even if it isn't, getting the
+ unwind info right helps debugging. */
+static void
+df_byte_lr_confluence_0 (basic_block bb)
+{
+ struct df_byte_lr_problem_data *problem_data
+ = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
+ bitmap op1 = df_byte_lr_get_bb_info (bb->index)->out;
+ if (bb != EXIT_BLOCK_PTR)
+ bitmap_copy (op1, problem_data->hardware_regs_used);
+}
+
+
+/* Confluence function that ignores fake edges. */
+
+static void
+df_byte_lr_confluence_n (edge e)
+{
+ struct df_byte_lr_problem_data *problem_data
+ = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
+ bitmap op1 = df_byte_lr_get_bb_info (e->src->index)->out;
+ bitmap op2 = df_byte_lr_get_bb_info (e->dest->index)->in;
+
+ /* Call-clobbered registers die across exception and call edges. */
+ /* ??? Abnormal call edges ignored for the moment, as this gets
+ confused by sibling call edges, which crashes reg-stack. */
+ if (e->flags & EDGE_EH)
+ bitmap_ior_and_compl_into (op1, op2, problem_data->invalidated_by_call);
+ else
+ bitmap_ior_into (op1, op2);
+
+ bitmap_ior_into (op1, problem_data->hardware_regs_used);
+}
+
+
+/* Transfer function. */
+
+static bool
+df_byte_lr_transfer_function (int bb_index)
+{
+ struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb_index);
+ bitmap in = bb_info->in;
+ bitmap out = bb_info->out;
+ bitmap use = bb_info->use;
+ bitmap def = bb_info->def;
+
+ return bitmap_ior_and_compl (in, use, out, def);
+}
+
+
+/* Free all storage associated with the problem. */
+
+static void
+df_byte_lr_free (void)
+{
+ struct df_byte_lr_problem_data *problem_data
+ = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
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